This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-174067, filed Jun. 21, 1999, the entire contents of which are incorporated herein by reference.
This invention relates to a method for making diagnosis for the displacements of respective constituent:elements in an image read-out apparatus and, in particular, a method for making self-diagnosis for a positional displacement and angle displacement of optical members such as mirrors and lens in a scanner section of a digital copier.
The digital copier includes a scanner section for reading out an image of a document and a printer section for copying the read-out image. The scanner section directs light onto a document placed on a document glass and receives reflected light and, after a conversion to an electric signal, obtains corresponding image data. The printer section allows a laser beam which is energized based on the obtained image data to be directed onto a read surface of a charged photosensitive drum to form an electrostatic latent image on the drum surface, develops the electrostatic latent image by a developing agent to a visible one, transfers it to a recording medium and outputs a corresponding image on the recording medium.
After the shipment of such a kind of digital copier, diagnosis is made, as a maintence and inspection operation, to see whether or not any displacement occurs in the respective constituent elements in the printer section and, by doing so, adjustment is made and another adjustment is also made by making diagnosis for the positional displacement of respective optical members in the scanner section.
First, based on a test-use image data initially prepared in the digital copier, a test image is output onto the recording medium through the printer section. At this time, the scanner section is not operated. And, by inspecting an output test image, the operator checks whether or not any displacement occurs in the respective: constituent elements in the printer section and manually adjusts the displacement of involved constituent elements.
After, in this way, any displacement of the constituent elements in the printer section has been adjusted, the operator places an adjustment-use chart on the document glass, reads out the chart through the scanner section and, based on the image data relating to the read-out chart, prints the test image on the recording medium through the printer section. And the operator checks the printed test image to make diagnosis for the distortion, displacement, etc., of the image and adjusts the involved optical members in the scanner section.
In the above-mentioned conventional method, even if, for example, the displacement only of the scanner section is to be adjusted, it is necessary to first adjust the printer section and it takes a long time and cumbersome operation for the operator to do adjustment. In this case, if the printer section is not accurately adjusted, any improper adjustment of the displacement at the printer section imparts an adverse influence to the adjustment of the scanner section, so that it is not possible to accurately adjust the scanner section.
Further, since, with respect to the adjustment of the scanner section, the test image is printed out with the test-use chart set on the document glass, it is necessary for the operator to manually set the chart on the document glass. It is not possible, therefore, to make automatic adjustment. Further, it is also necessary to prepare a plurality of kinds of test-use charts corresponding to the adjustment items and make test-printing. This takes a lot of time and labor.
Further, since diagnosis is made for the displacement of the scanner section by checking the printed-out test image by the eye of the operator, this evaluation differs from operator to operator, thus presenting a problem. In the case where the displacement of the scanner section is relatively small, the displacement and distortion of a test-printed image are small and their evaluation is sometimes difficult even if they are checked by the eye of the operator. In this case, the test-printed recording medium has sometimes to be copied and, by doing so, the displacement and distortion of the image is enlarged for the operator to evaluate them properly.
This invention is achieved with the above-mentioned points in view and it is accordingly the object of the present invention to provide a displacement diagnosing method applied to an image pick-up apparatus which can make accurate diagnosis for the displacement of respective constituent elements in the image read-out apparatus, for a shorter time, and obtain a high reliable result of diagnosis.
In order to achieve the above-mentioned object of this invention there is provided a displacement diagnosing method applied to an image read-out apparatus having a light source for illuminating a document with light, an optical element for allowing light which is reflected from the document to be received and detecting a corresponding image signal, and a plurality of optical members for guiding the reflected light from the document to the optical element, the method comprising the steps of: directing light from the light source to a mark provided on a body of the image pick-up apparatus in a position adjacent to the document; guiding the reflected light to the optical element through the optical members to allow an image signal relating to the mark to be detected by the optical element; and, based on the detected image signal, making diagnosis for displacements of those constituent elements of the image read-out apparatus including the light source, optical members and optical element.
Further according to this invention there is provided a displacement diagnosing method applied to an image read-out apparatus having a light source for illuminating a document with light, an optical element for allowing light which is reflected from the document to be received and detecting a corresponding image signal and a plurality of optical members for guiding the reflected light from the document to the optical element, the method using a diagnosis chart provided on a body of the image read-out apparatus in a position adjacent to the document and including a first mark having line segment extending in a first direction along the document and line segments oblique to the first direction and a second mark having a plurality of sets of black/white pair lines extending in the first direction and arranged along a second direction perpendicular to the first direction and using a plurality of photoelectric conversion elements provided at the optical element and arranged along the second direction and comprising the steps of: directing the light from the light source to the chart; guiding the reflected light through the optical members to the photoelectric conversion elements in the optical element to detect an image signal relating to the first and second marks; and, based on the detected image signal, making diagnosis for the displacements of constituent elements of the image read-out apparatus including the light source, optical members and optical element.
Further according to this invention there is provided a displacement diagnosing/adjusting method applied to an image read-out apparatus having a light source for illuminating a document with light, an optical element for allowing light which is reflected from the document to be received and detecting a corresponding image signal and a plurality of optical members for guiding the reflected light from the document to the optical element, the method comprising the steps of: directing light from the light source onto a mark provided on a body of the image read-out apparatus in a position adjacent to the document; guiding the reflected light through the optical members to the optical element to detect an image signal relating to the mark; based on the detected image signal, making self-diagnosis, by the image read-out apparatus, for the displacements of constituent elements of the image read-out apparatus including the light source, optical members and optical element, and automatically adjusting the displacements of the constituents involved as a result of self-diagnosis.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.